 
Summary: More Results on rInflated Graphs: Arboricity, Thickness,
Chromatic Number, and Fractional Chromatic Number
Michael O. Albertson
L. Seelye Clark Professor of Mathematics
Department of Mathematics and Statistics
Smith College, Northampton MA 01063
Debra L. Boutin
Department of Mathematics
Hamilton College, Clinton, NY 13323
dboutin@hamilton.edu
Ellen Gethner
Department of Computer Science
University of Colorado Denver, Denver, CO 80217
ellen.gethner@ucdenver.edu
September 8, 2010
1 Introduction
In 1890, P. J. Heawood published his famous article Mapcolour theorem in the Quar
terly Journal of Mathematics [Hea90] that illustrated the flaw in A.B. Kempe's "proof"
of the Four Colour Theorem [Kem79]. Heawood's main intention was to investigate gen
eralizations of the Four Colour Problem "of which strangely the rigorous proof is much
